They cut down on them using PUBLIC funding! But clearly if Obama can commission them to do a study, then they can still perform some studies. And while they did indeed find that guns are bad, they also found that they're more likely to be used for defensive purposes.

You understand that the vast majority of research conducted in the United States has public funding, right? And so removing public funding from gun research is tremendously damaging to gun violence research.https://goo.gl/images/YG3B5n

To remove public funding from gun research, but they didn't totally restrict it. Also, public funding is mostly used for scientific research. Either way though, this was commissioned by Obama, and whatever else you may think about guns, the study (And certainly not the only one.) does pretty much conclude that they are used more for defense than crime.